Improving the fuel efficiency of a vehicle is a widely-desired goal in the automobile industry. In addition to the immediate effects of reduced cost of operation, vehicles which require less fuel impose a smaller burden on any resources on which they rely for power. Accordingly, improvements to vehicles which reduce the fuel required for operation have immediate application.
One source of fuel expenditure in vehicles is power for operating one or more cooling fans. Cooling fans are used to draw air across a radiator or other heat exchanger used to moderate the internal temperature of the vehicle's engine. Turning the cooling fans requires power, which is typically obtained from the same power source that provides power for propulsion of the vehicle. Thus, cooling fans often impose a power cost on vehicles. When not in use, they are usually idle to reduce their power cost.